Thanks Mark for your comments. The super pump was what the PC recommended. I was wondering about 2 speed pumps. Today I was offered a Pentair Challenger and 600# sand filter for a similar pool set up- 28,000 gal 40'6" x20'6" . I don't know if this is a 2-speed, but I don't think so. To be honest I dont know anything about pumps, head or pipe sizes, or filters. Thats why I have asked for help. How much better flow with 2" pipe that with 1 1/2" pipe? What type and size filter go together? My fear is that I will get the wrong size pump, filter, or piping and be stuck with it for several years. I was thinking that the right 2-speed pump, although more costly, would save electricity. Your thoughts and any suggestions about them? ( Is a super pump a 2 speed? a northstar) I don't care what hp, (just want a good pump) as long as I have water turnover often and can add slide and fountain later if I want to. I don't understand head and all that technical stuff. I need specific advice, and I will certainly talk to PC about the things that you suggest. Thanks again